Sorry to enter this one late but I have just spotted something. You cannot run these systems without the knock sensor(s) attached to the engine. Knock sensors are in fact microphones listening to the engine and if the system cannot 'hear' the background noise of a running engine , it defaults to 'safe mode' i.e. full retard. In normal operation it 'listens' for excessive noise in the right frequency band on each compression stroke. This means that excessive 'noise' whether mechanical OR electrical interference can be interpreted as knock. I therefore agree with the other learned gentlemen above who suggest low oil , electrical interference from wrong spark-plugs (possibly Japanese variety?)or noise due to excess engine wear.